.tree * {
  padding: 0;
  margin: 0;
  font-family: '宋体', Arial, Helvetica, AppleGothic, sans-serif;
}
.tree {
  font-size: 12px;
  width: 300px;
  height: 155px;
  overflow: auto;
  user-select: none;
  padding: 10px;
}
.tree ul,
li {
  list-style: none;
  white-space: nowrap;
}
.tree .button {
  display: inline-block;
  width: 16px;
  height: 16px;
  vertical-align: middle;
  cursor: pointer;
}
.tree .button.button-close {
  background: url('./icon/add.png') no-repeat center;
}
.tree .button.button-open {
  background: url('./icon/minus.png') no-repeat center;
}
.tree .button.button-nochild {
  background: none;
}

.tree .icon {
  display: inline-block;
  width: 16px;
  height: 18px;
  margin-right: 3px;
  cursor: pointer;
  user-select: none;
  vertical-align: middle;
}
.tree .icon-close {
  background: url('./icon/close.png') no-repeat center;
}
.tree .icon-open {
  background: url('./icon/open.png') no-repeat center;
}
.tree .icon-nochild {
  background: url('./icon/no-child.png') no-repeat center;
}
.tree li a {
  display: inline-block;
  height: 17px;
  cursor: pointer;
  color: #333333;
  background-color: transparent;
  text-decoration: none;
  vertical-align: top;
  padding: 0 3px;
}
.tree li a.a_selected {
  padding-top: 0px;
  color: #ffffff;
  opacity: 0.8;
  background-color: #007fff;
}
.tree .node_name {
  display: inline-block;
  vertical-align: middle;
}

.tree li ul {
  padding-left: 18px;
}
